1. Field of the Invention
This invention relates to a method for anastomosizing small vessels.
2. Description of the Prior Art
Microsurgery procedures require anastomosis of small vessels, e.g., veins and arteries, which may have a diameter of 0.4-1.5 millimeters. When open ends of such small vessels are to be joined (anastomosis) the recommended procedure is to provide 6-to-8 sutures for a vein-to-vein connection and 7-to-9 sutures for an artery-to-artery connection. Typical sutures are 0.3 to 0.4 millimeters wide. Because of the size of the vessels and sutures, these procedures are carried out with use of a microscope and are referred to as microsurgery techniques.
Overwhelmingly, such anastomosis procedures employ a clamping device which secures the cut ends of the vessel in alignment. See U.S. Pat. No. 4,553,542. A normal procedure employs microsurgery forceps which are inserted through the open end into one of the vessels and allowed to spring open whereby the vessel end region is dilated to facilitate puncturing that vessel with a suture needle. The forceps are withdrawn and inserted through the open end of the other vessel for dilation and the suture needle point punctures the dilated vessel surface. The suture needle is extracted from both vessels and the trailing suture is tied. This sequence is repeated numerous times for each vessel. The initial sutures are usually spaced diametrically apart on the vessels and can be applied without significant difficulty. Subsequent sutures however are quite difficult with the microsurgery forceps technique because of the small size of the vessels. Typically, anastomosis of a single vessel using the microsurgery forceps techniques may require about one hour of surgical time. The success of overall surgical procedures frequently depends upon the success of blood vessel anastomosis procedures. An alternative existing procedure employs a ring device which is mounted annularly from the anastomosis site as described in U.S. Pat. No. 4,474,181. This procedure dilates the ends of the vessels and maintains the anastomosis suture connection in a dilated condition by connecting each suture to the annular ring. Each suture is normally applied with the microsurgery forceps technique when a ring device is used.
In co-pending patent application Ser. No. 914,164, which is assigned to the Assignee of this patent application, an anastomosis tool is described which resembles a tack-lifter having a thin shaft and a pair of projecting tines which receive the point of a suture needle penetrating an open end of a first small vessel and divert the suture needle point toward the open end of a second vessel; the tool then is positioned on the outer surface of the second vessel end to support the second vessel wall while the suture needle point is forced outwardly through the second vessel wall.